Device Switching

I have to take my 6 Plus into my local Apple Store tomorrow to replace it with another; my rear camera seems to have lost its ability to focus. Close up, it's focused but not up to infinite. Everything distant is blurry.

I am wondering which is the best software to use so that I can copy all data onto a PC, replace the device and then download the data back onto the new device as if nothing has changed. I forget what the term is called… mirroring?

iTunes backup
Install iTunes into your computer, connect your iPhone to your computer, run iTunes, select your iPhone in the iTunes window, and perform a backup.
When you get your new iPhone, you will connect it to your computer, open up iTunes, click on the iPhone in iTunes windows and click on restore backup.
After backup restore is done, everything will be like it is in your iPhone now.

iTunes...sync to make sure apps and media are all coordinated between the old phone and computer... Then backup the old phone to iTunes... Then sync the new phone and restore the backup... The folks at the AppleStore will be able to help you do a restore from an iCloud backup.

Use iTunes, transfer your purchases, select the option where you can encrypt the backup so it will also store all passwords, hit the backup button and when you finally have your new device, simply use restore backup option.

I have to take my 6 Plus into my local Apple Store tomorrow to replace it with another; my rear camera seems to have lost its ability to focus. Close up, it's focused but not up to infinite. Everything distant is blurry.

I am wondering which is the best software to use so that I can copy all data onto a PC, replace the device and then download the data back onto the new device as if nothing has changed. I forget what the term is called… mirroring?

Anyway. Thanks for the help!

Use iCloud backup. Apple can restore the replacement phone with your previous backup right there in the store and you walk out ready to go.